The present application relates to micro-light emitting diodes (LEDs) which are present on a display substrate, and more particularly to various methods of transferring micro-LEDs from a temporary support substrate to a surface of a display substrate.
A light emitting diode (LED) is a two-lead semiconductor light source. An LED is a p-n junction diode, which emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescene, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor material used to provide the p-n junction.
There is an interest in fabricating high resolution display technology using multiple colored micro-LEDs (i.e., LED chiplets) to form individual pixels. An important challenge lies in the precise placement of individual micro-LEDs corresponding to the different colors. Although technologies exist which combine temporary bonding and release of singulated LEDs, the placement precision required, while retaining high throughput and low-cost, remains lacking.